JP4808112B2 - Dust remover and operation method of dust remover - Google Patents

Description

  The present invention relates to a dust remover and a method of operating the dust remover, and is particularly useful when applied to a dust remover in an environment where the load on the dust remover suddenly increases due to a large amount of dust adhering. It is a thing.

  For example, a thermal power plant is provided with a condenser for cooling steam generated by a boiler, and seawater is used as cooling water for the condenser. Usually, a dust remover is provided on the water channel through which the condenser takes in the cooling water, thereby preventing dust from being taken into the condenser (for example, see Patent Document 1).

  There are various types of dust removers depending on the type of dust trapping method, and one of them is a net type dust remover. In the net-type dust remover, a portion (screen) that captures dust is formed in a mesh shape (for example, a wire mesh or the like). Furthermore, this screen is formed in an endless shape, and is stretched around the sprocket so as to be able to circulate and move. And the lower part of a screen is arrange | positioned in a water channel so that an upper part may be exposed on a water channel. That is, when the dust flows into the water channel, the dust adheres to the screen, so that the dust does not flow downstream of the screen.

  When the dust adhering to the screen increases, the flow of water passing through the screen is hindered, the amount of water flowing downstream is reduced, and for example, the amount of cooling water supplied to the condenser on the downstream side of the water channel is insufficient. Become.

  When dust adheres to the screen in this way, there is a difference in the water level between the upstream side and the downstream side of the screen. By detecting this, various devices are operated to remove the dust attached to the screen. ing. For example, the pump is first operated to take water, and the pressure of the water is increased to a predetermined pressure value. After the pressure increase is completed, the water is injected toward the inner surface of the screen through the injection nozzle. When the water boosted by the pump reaches a predetermined value, the motor is driven to rotate the sprocket. As a result, the dust adhering to the screen in the water channel moves in front of the spray nozzle as the screen circulates and is separated from the screen by the sprayed water and stored in a predetermined collection box.

  At this time, when the pressure of water is increased using the self-priming pump, it takes several minutes for the water pressure to reach a predetermined pressure value after the self-priming pump is operated. During this time, since the screen does not circulate, for example, if a large amount of jellyfish or the like adheres to the screen, the jellyfish or the like becomes a resistance and the load when the screen is circulated increases. For this reason, when the motor is driven after the water reaches a predetermined pressure value by the self-priming pump that has been operated first, the motor tries to rotate the sprocket with a large torque corresponding to the load, so that the drive system There arises a problem that each of the parts is damaged.

  For example, a shear pin is provided as a safety device at a portion where the sprocket of the drive speed reduction device is fixed, and the shear pin is cut to protect the sprocket and the like when an excessive torque is applied from the motor. As a result, the motor torque is not transmitted to the sprocket, and the screen also does not circulate. Furthermore, jellyfish adhering to the screen is more and more concentrated on a part of the water channel of the screen, obstructing the water flow, and there is a problem that the supply of water to the condenser etc. arranged downstream of the screen is delayed. May occur.

  On the other hand, it is possible to avoid this problem by using a non-self-priming pump that can pressurize water and spray it on the screen in a short time instead of using a self-priming pump, but it takes installation and maintenance. Cost is more expensive than a self-priming pump.

Japanese Patent Laid-Open No. 8-177029

  In view of such circumstances, the present invention provides a dust remover that reliably collects dust even when the load applied to the dust remover suddenly increases due to a large amount of dust attached, and a method of operating the dust remover. With the goal.

In order to achieve the above object, the first aspect of the present invention is supported by a pair of sprockets arranged in the water channel and above the water channel so that the rotation axis is substantially orthogonal to the water flow. An aqueous endless screen, drive means for circulating the screen through the pair of sprockets, pumping water from the water channel and increasing the pressure, and facing the inner surface of the screen A self-priming pump that supplies pressurized water to the spray nozzle, and the self-priming pump is operated by detecting that the water level difference between the upstream side and the downstream side of the screen exceeds a first threshold. And a dust remover comprising a control means for detecting that the pressure value of the water boosted by the self-priming pump has reached a predetermined value and driving the drive means. When it is detected that the water level difference has become greater than or equal to the second threshold value, which is greater than the first threshold value, from when the self-priming pump is operated until the pressure value of the pumped water reaches the predetermined value. In the dust remover, the driving means is driven to circulate the screen from a stopped state .

  In such a first aspect, the control means determines whether or not dust has adhered to the screen by calculating the water level difference between the upstream side and the downstream side of the screen. Drive the suction pump. Further, the control means detects that the pressure value of the water boosted by the self-priming pump has reached a predetermined value, and then drives the drive means to circulate the screen. As a result, a part of the screen to which the dust is attached circulates and moves to the front of the self-priming pump, and the dust is separated from the screen by the pressure of water sprayed from the spray nozzle.

  On the other hand, when a large amount of dust adheres to the screen between the time when the control means first drives the self-priming pump and the pressure value of water boosted by the self-priming pump reaches a predetermined value, On the condition that the water level difference is further increased, the screen is circulated and moved quickly by driving the driving means.

  As a result, the screen can be circulated and moved before a large amount of dust is concentrated on a part of the screen immersed in the water channel. Therefore, since the driving means does not rotate the sprocket with an excessive torque, it is possible to prevent damage to the sprocket and the shear pin provided on the sprocket. As a result, it is possible to reliably collect the dust and keep the water flow in the water channel well.

  Moreover, since the self-priming pump is less expensive than other types of pumps, the manufacturing cost of the entire dust remover can be reduced. In addition, since the self-priming pump can be easily disassembled and inspected, the burden on maintenance work of the dust remover can be reduced.

In the second aspect of the present invention, the rotating shaft is supported by a pair of sprockets disposed in the water channel and above the water channel so as to be substantially orthogonal to the water flow, and is water-permeable and endless. The formed screen, driving means for circulating and moving the screen through the pair of sprockets, pumping water from the water channel and increasing the pressure, and increasing the pressure to the spray nozzle disposed on the inner surface of the screen A method of operating a dust remover comprising a self-priming pump to be supplied, wherein the self-priming pump is detected by detecting that a water level difference between an upstream side and a downstream side of the screen exceeds a first threshold value. Is operated, and when the pressure value of the water boosted by the self-priming pump reaches a predetermined value, the driving means is driven and the self-priming pump is operated and then pumped. During pressure value clogs water to reach the predetermined value, wherein when the water level difference is detected that a first threshold value larger than the second threshold value or more, by driving the driving means In the method of operating a dust remover, the screen is circulated and moved from a stopped state .

  In the second aspect, it is determined whether dust has adhered to the screen. If the dust has adhered to the screen, the self-priming pump is driven, and the pressure value of the water boosted by the self-priming pump is After detecting that the predetermined value has been reached, the driving means is driven.

  On the other hand, if a large amount of dust adheres to the screen between the time when the self-priming pump is first driven and the pressure value of the water boosted by the self-priming pump reaches a predetermined value, the water level difference increases. When this is detected, the drive means is immediately driven to circulate the screen.

  As a result, the screen can be circulated and moved before a large amount of dust is concentrated on a part of the screen immersed in the water channel. Therefore, since the driving means does not rotate the sprocket with an excessive torque, it is possible to prevent damage to the sprocket and the shear pin provided on the sprocket. As a result, it is possible to reliably collect the dust and keep the water flow in the water channel well.

  According to the present invention, even when the load applied to the dust remover suddenly increases due to a large amount of dust adhering, the dust can be reliably recovered. Thereby, the water flow of a waterway can be maintained favorable and it can avoid without delaying supply of the water to a downstream side.

  Hereinafter, the best mode for carrying out the present invention will be described. The description of the present embodiment is an exemplification, and the present invention is not limited to the following description.

  FIG. 1 is a schematic side view of a dust remover according to the present embodiment.

  As shown in FIG. 1, the drive sprocket 20 is disposed above the water channel so that its rotational axis is substantially orthogonal to the water flow A (from left to right in the figure). The driven sprocket 21 is also disposed in the water channel and below the drive sprocket 20 so that its rotational axis is substantially orthogonal to the water flow A.

  Further, a screen 10, which is an endless metal mesh having a width substantially the same as the length of the water channel in the width direction, is stretched around the drive sprocket 20 and the driven sprocket 21. That is, the screen 10 is arranged so that the surface thereof is substantially orthogonal to the water flow A. As a result, the water passes through the screen 10 from the upstream to the downstream, while the dust 70 flowing in by the water flow A is the mesh of the screen 10. Adhere to the part.

  The motor 30 is configured to transmit power to the drive sprocket 20 via the chain 31. Specifically, the motor 30 is provided with a reduction gear (not shown), and a chain 31 is attached to a sprocket 33 provided in the reduction gear. Further, a shear pin 32 is provided as a safety device at a portion where the sprocket 33 of the speed reducer is fixed.

  As will be described later, On / Off of the motor 30 is controlled based on a control signal from the control unit 60. At this time, the motor 30 rotates the drive sprocket 20 so that the upstream surface of the screen 10 circulates from bottom to top (B in the figure) and the downstream surface from top to bottom (C in the figure).

  On the other hand, an injection nozzle 41 is disposed inside the screen 10 with its injection port directed toward the inner surface on the downstream side of the screen 10, and water pressurized to a predetermined pressure value by the self-priming pump 40 is supplied. The pressurized water is sprayed toward the inner surface.

  That is, when the motor 30 is driven, the screen 10 circulates, and a part of the screen 10 with the dust 70 attached in the water channel moves to the front of the injection nozzle 41. Then, the dust 70 is separated from the screen 10 by the pressure of the water sprayed by the spray nozzle 41 and falls into the collection box 42 provided on the downstream side of the screen 10.

Control unit 60, the upstream water level meter 50 and, downstream water level meter 51. Each water level from W ₁ to measure the water level W ₂ on the downstream side of the screen 10 for measuring the water level W ₁ of the upstream side of the screen 10, It receives data W _2, and determines whether the dust 70 is attached to the screen 10 based on this data. When it is determined that the dust 70 is not attached, the control unit 60 does not operate the motor 30 and the self-priming pump 40, and operates them when the dust 70 is attached.

More specifically, when the dust 70 does not flow into the water channel, the screen 10 does not serve as a barrier for the water flow A, and therefore the water level W ₁ and the water level W ₂ are substantially equal. Therefore, when the water level W ₁ and the water level W ₂ are substantially equal, it can be determined that the dust 70 is not attached to the screen 10. On the other hand, when the dust 70 adheres to the screen 10, clogging occurs in the screen 10, gradually water level difference H of the water level W ₁ and water level W ₂ is increased. Therefore, when there is a water level difference H, it can be determined that the dust 70 is attached to the screen 10.

  In principle, when the control unit 60 detects that the water level difference H is equal to or greater than the first threshold and determines that the dust 70 has adhered to the screen 10, the control unit 60 operates the self-priming pump 40 to After detecting that the pressure value of the water pressurized by the suction pump 40 has reached a predetermined value, the motor 30 is driven. This is because it takes about several minutes after the self-priming pump 40 is operated until the pressure of water is increased to a predetermined pressure value (hereinafter, this time is referred to as “preparation time” for convenience). That is, it is for driving the motor 30 in a state where water is sprayed from the spray nozzle 41 to circulate and move the screen 10, thereby reliably separating the dust 70 from the screen 10.

  On the other hand, when a large amount of dust 70 flows into the water channel, more dust 70 adheres to the screen 10 when the initial water level difference H is detected and the self-priming pump 40 is operated to complete the preparation time. The water level difference H is further increased. Therefore, the control unit 60 determines that a large amount of dust 70 has adhered to the screen 10 when detecting that the initially calculated water level difference H further increases and becomes equal to or greater than the second threshold, and the drive sprocket 20 The motor 30 is driven promptly so that excessive torque is not applied to the motor. That is, the motor 30 detects that a large amount of dust 70 has adhered to the screen 10 and rotates the drive sprocket 20 regardless of whether the preparation time of the self-priming pump 40 has elapsed. As a result, when the motor 30 rotates the drive sprocket 20, the drive sprocket 20 can be rotated with a smaller torque than when the drive sprocket 20 is rotated after the preparation time has elapsed. By avoiding this, the drive sprocket 20 can be rotated to reliably lift the dust 70 out of the water channel and remove it.

  FIG. 2 is a diagram illustrating a processing procedure in which the control unit controls the self-priming pump and the motor. The control of the self-priming pump 40 and the motor 30 by the control unit 60 will be described with reference to FIG.

First, to calculate the water level difference H between the water level W ₁ and water level W ₂ obtained from the upstream side water level meter 50 and the downstream water level meter 51, (step S1).

Next, it is determined whether or not the water level difference H is equal to or greater than a first threshold value (step S2). In the present embodiment, for example, 350 mm is used as the first threshold value. When the water level difference H is less than 350 mm (step S2: No), after a predetermined time has elapsed, the water level W ₁ and the water level W ₂ are acquired again and the water level difference H is measured (step S1). On the other hand, when the water level difference H is 350 mm or more, it is determined that the dust 70 has adhered to the screen 10, and the self-priming pump 40 is operated (step S3).

  After the self-priming pump 40 is operated, whether or not the water level difference H is equal to or greater than the second threshold until the water pressure increased by the self-priming pump 40 reaches a predetermined pressure value (preparation time). Is determined (step S4). In the present embodiment, for example, 450 mm is used as the second threshold value. When the water level difference H is less than 450 mm (step S4: No), it is determined whether or not the pressure value of the water pressurized by the pump is equal to or higher than a predetermined value (step S5). In the present embodiment, for example, 0.2 MPa is used as the predetermined value. Next, if the pressure value is 0.2 MPa or more (step S5: Yes), the motor 30 is driven (step S6). If the pressure value is less than 0.2 MPa (step S5: No), after a predetermined time has passed, it is determined again whether the water level difference H is 450 mm or more (step S4).

  On the other hand, when the water level difference H becomes 450 mm or more due to the large amount of dust 70 adsorbed on the screen 10 during the preparation time (step S4: Yes), the motor 30 is operated (step S6). That is, the motor 30 is driven and the screen 10 circulates regardless of the progress of pressure increase of the water by the self-priming pump 40. As a result, in order to drive the motor 30 quickly before the preparation time of the self-priming pump 40 elapses, the screen 10 is circulated before the large amount of dust 70 intensively adheres to a part of the screen 10 immersed in the water channel. Can be moved. Accordingly, since the motor 30 does not rotate the drive sprocket 20 with an excessive torque, the drive sprocket 20 and the shear pin 32 can be prevented from being damaged.

  Even if the self-priming pump 40 is used as the pump used in the dust remover 1, the control by the control unit 60 as described above is performed, as in the case of using an expensive non-self-priming pump. The breakage can be avoided and the dust 70 can be reliably lifted and removed from the water channel to keep the water flow A good. Further, since the self-priming pump 40 is inexpensive and can be easily disassembled and inspected, it is possible to reduce the manufacturing cost of the dust remover 1 as a whole and to reduce the work load for maintenance. it can.

  As described above, the dust remover 1 according to the present embodiment is configured so that the load applied to the motor 30, the drive sprocket 20 and the like suddenly increases due to a large amount of dust 70 adhering to the screen 10. The dust 70 can be reliably recovered without damaging 30 and the like, and the water flow in the water channel can be kept good.

  The present invention can be used in industries that use water intake from waterways.

It is a schematic side view of the dust remover according to the present embodiment. It is a figure which shows the process sequence which the control part of the dust remover which concerns on this embodiment controls a self-priming pump and a motor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dust remover 10 Screen 20 Drive sprocket 21 Driven sprocket 30 Motor 31 Chain 32 Shear pin 33 Sprocket 40 Self-priming pump 41 Injection nozzle 42 Collection box 50 Upstream side water level measuring device 51 Downstream side water level measuring device 60 Control part 70 Dust

Claims (2)

A screen formed in an endless shape having water permeability and supported by a pair of sprockets arranged in the water channel and above the water channel so that the rotation axis is substantially orthogonal to the water flow, and being circulated and movable.
Drive means for circulating and moving the screen through the pair of sprockets;
A self-priming pump that pumps water from a water channel and pressurizes it, and supplies the pressurized water to an injection nozzle disposed facing the inner surface of the screen;
The self-priming pump is operated by detecting that the water level difference between the upstream side and the downstream side of the screen is equal to or greater than a first threshold, and the pressure value of the water boosted by the self-priming pump is In a dust remover comprising a control means for detecting that a predetermined value has been reached and driving the drive means,
In the control means, the water level difference becomes equal to or greater than a second threshold value greater than the first threshold value until the pressure value of the pumped water reaches the predetermined value after the self-priming pump is operated. When it is detected, the screen is circulated and moved from the stopped state by driving the driving means. A screen formed in an endless shape having water permeability and supported by a pair of sprockets arranged in the water channel and above the water channel so that the rotation axis is substantially orthogonal to the water flow, and being circulated and movable.
Drive means for circulating and moving the screen through the pair of sprockets;
A method of operating a dust remover comprising a self-priming pump that pumps water from a water channel and boosts the pressure, and supplies the pressurized water to an injection nozzle disposed facing the inner surface of the screen,
The self-priming pump is operated by detecting that the water level difference between the upstream side and the downstream side of the screen is equal to or greater than a first threshold, and the pressure value of the water boosted by the self-priming pump is Detecting that the predetermined value has been reached and driving the driving means;
It was detected that the water level difference was equal to or greater than a second threshold value greater than the first threshold value between the time when the self-priming pump was operated and the pressure value of the pumped water reached the predetermined value. In such a case, the dust removing machine operating method is characterized in that the screen is circulated and moved from a stopped state by driving the driving means.

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